diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/internal/subtle')
3 files changed, 117 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/internal/subtle/aliasing.go b/vendor/golang.org/x/crypto/internal/subtle/aliasing.go new file mode 100644 index 0000000..f38797b --- /dev/null +++ b/vendor/golang.org/x/crypto/internal/subtle/aliasing.go @@ -0,0 +1,32 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !appengine + +// Package subtle implements functions that are often useful in cryptographic +// code but require careful thought to use correctly. +package subtle // import "golang.org/x/crypto/internal/subtle" + +import "unsafe" + +// AnyOverlap reports whether x and y share memory at any (not necessarily +// corresponding) index. The memory beyond the slice length is ignored. +func AnyOverlap(x, y []byte) bool { + return len(x) > 0 && len(y) > 0 && + uintptr(unsafe.Pointer(&x[0])) <= uintptr(unsafe.Pointer(&y[len(y)-1])) && + uintptr(unsafe.Pointer(&y[0])) <= uintptr(unsafe.Pointer(&x[len(x)-1])) +} + +// InexactOverlap reports whether x and y share memory at any non-corresponding +// index. The memory beyond the slice length is ignored. Note that x and y can +// have different lengths and still not have any inexact overlap. +// +// InexactOverlap can be used to implement the requirements of the crypto/cipher +// AEAD, Block, BlockMode and Stream interfaces. +func InexactOverlap(x, y []byte) bool { + if len(x) == 0 || len(y) == 0 || &x[0] == &y[0] { + return false + } + return AnyOverlap(x, y) +} diff --git a/vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go b/vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go new file mode 100644 index 0000000..0cc4a8a --- /dev/null +++ b/vendor/golang.org/x/crypto/internal/subtle/aliasing_appengine.go @@ -0,0 +1,35 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build appengine + +// Package subtle implements functions that are often useful in cryptographic +// code but require careful thought to use correctly. +package subtle // import "golang.org/x/crypto/internal/subtle" + +// This is the Google App Engine standard variant based on reflect +// because the unsafe package and cgo are disallowed. + +import "reflect" + +// AnyOverlap reports whether x and y share memory at any (not necessarily +// corresponding) index. The memory beyond the slice length is ignored. +func AnyOverlap(x, y []byte) bool { + return len(x) > 0 && len(y) > 0 && + reflect.ValueOf(&x[0]).Pointer() <= reflect.ValueOf(&y[len(y)-1]).Pointer() && + reflect.ValueOf(&y[0]).Pointer() <= reflect.ValueOf(&x[len(x)-1]).Pointer() +} + +// InexactOverlap reports whether x and y share memory at any non-corresponding +// index. The memory beyond the slice length is ignored. Note that x and y can +// have different lengths and still not have any inexact overlap. +// +// InexactOverlap can be used to implement the requirements of the crypto/cipher +// AEAD, Block, BlockMode and Stream interfaces. +func InexactOverlap(x, y []byte) bool { + if len(x) == 0 || len(y) == 0 || &x[0] == &y[0] { + return false + } + return AnyOverlap(x, y) +} diff --git a/vendor/golang.org/x/crypto/internal/subtle/aliasing_test.go b/vendor/golang.org/x/crypto/internal/subtle/aliasing_test.go new file mode 100644 index 0000000..a5b62ff --- /dev/null +++ b/vendor/golang.org/x/crypto/internal/subtle/aliasing_test.go @@ -0,0 +1,50 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package subtle_test + +import ( + "testing" + + "golang.org/x/crypto/internal/subtle" +) + +var a, b [100]byte + +var aliasingTests = []struct { + x, y []byte + anyOverlap, inexactOverlap bool +}{ + {a[:], b[:], false, false}, + {a[:], b[:0], false, false}, + {a[:], b[:50], false, false}, + {a[40:50], a[50:60], false, false}, + {a[40:50], a[60:70], false, false}, + {a[:51], a[50:], true, true}, + {a[:], a[:], true, false}, + {a[:50], a[:60], true, false}, + {a[:], nil, false, false}, + {nil, nil, false, false}, + {a[:], a[:0], false, false}, + {a[:10], a[:10:20], true, false}, + {a[:10], a[5:10:20], true, true}, +} + +func testAliasing(t *testing.T, i int, x, y []byte, anyOverlap, inexactOverlap bool) { + any := subtle.AnyOverlap(x, y) + if any != anyOverlap { + t.Errorf("%d: wrong AnyOverlap result, expected %v, got %v", i, anyOverlap, any) + } + inexact := subtle.InexactOverlap(x, y) + if inexact != inexactOverlap { + t.Errorf("%d: wrong InexactOverlap result, expected %v, got %v", i, inexactOverlap, any) + } +} + +func TestAliasing(t *testing.T) { + for i, tt := range aliasingTests { + testAliasing(t, i, tt.x, tt.y, tt.anyOverlap, tt.inexactOverlap) + testAliasing(t, i, tt.y, tt.x, tt.anyOverlap, tt.inexactOverlap) + } +} |